Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the OnStar button assembly.
- Ignition ON, test for less than 1 volt at the keypad signal terminal 11.
- If greater than specified value, test the circuit for short to voltage. If the circuit tests normal, test or replace the VCIM.
- Test for less than 1 ohm of resistance between the VCIM and OnStar button assembly.
- If greater than specified value, test the circuit for open/high resistance, or for short to ground.
- If the circuit tests normal, test or replace the OnStar button assembly.